The purpose of this open-label prospective optimization and phase I/II clinical trial is to examine the safety, optimal dose, targeting, dosimetry and efficacy of PRAIT using the humanized anti-CEA x anti-HSG bsMAb TF2 and the 177Lu-IMP-288 peptide pretargeted in patients with CEA-positive SCLC or CEA-expressing Non Small Cell Lung Carcinoma (NSCLC)